Maternity leave given for 3 months by employer - any clause in maternity benefit act for extension?

I have joined as senior research fellow in national institute on 30 May 2018 n my tenure ended on 30 may 2019. I gave birth to girl child on 24 Feb 2019. I got maternity leave till my tenure end i.e 30 May 2019. I have applied for tenure extension of my services in institute for which I got approval. So, can you please suggest me any clause in maternity benefit act for extension of my maternity leave as I am unable to attend duties with 3 months old kid.

Dear Sujatha,
When did you come to know about approval for the extension of your tenure? You could have applied immediately for the extension of maternity leave.
Anyway, even now also you may apply for the extension of the maternity. Since the delivery is already over, you may submit the certificate from the hospital authorities about your delivery. In case if you have obtained the birth certificate for a newly born child from the local municipal office, then you may attach that also.
Address your application to the head of the institute however, route your application through the proper channel.
By the way, heading of your post is misleading. Your maternity leave was sanctioned until the end of your tenure. Therefore, the authorities cannot be blamed per se for not adhering to the provisions of the Maternity Benefits Act, 1961. If you were not eligible to get maternity leave after 30th May 2019, then how the approving authorities would have sanctioned it? Institute authorities have done what best they could have done.
Thanks,
Dinesh Divekar